NGHIÊN CỨU VỀ THUẬT TOÁN KHAI PHÁ CÂY CON PHỔ BIẾN TRONG KHO CÁC CÂY DỮ LIỆU

Important issue in mining database of trees is to find frequent occurs of subtrees. Since the number of frequent subtrees usually grows exponentially with the size of subtrees, therefore mining all frequent subtrees become infeasible for large tree size with traditional methods. There are several techniques which are used to prune the branches of enumeration tree that do not correspond to frequent subtrees. One of these techniques is heuristic method which is used to compute and identify frequent subtrees. In this paper, we present the canonical form for labelled rooted unordered trees the breadth-first canonical form (BFCF), then the canonical forms are applied to the frequent subtree mining problem.